Louis Vuitton bags are nice and all, but the best gifts Kim Kardashian gives her kids are entirely custom. 

Explaining how challenging it can be to live up to her own best-mom-ever standards, the SKIMS founder shared the ace she has up her designer sleeve.

"Every year I write each one of my kids about a four or five-page letter on their birthday, about what the year was like, who their friends are, silly words they're saying, their favorite foods, all the silly things they do and a little journey of what the year is like," she revealed in the latest episode of the On Purpose with Jay Shetty podcast.   

And now that North, 9, Saint, 7, Chicago, 5, and Psalm, 4, have each built up quite the stack, "It's so fun to see from the first year now," she continued, "one of 'em is almost 10 years old. And I know that they'll appreciate this." 

And should she ever question if she's really doing amazing, sweetie, she just looks at her relationship with her own mom, Kris Jenner.

"I know that they'll appreciate everything, even if they might have thought I was being a little harsh on them," continued the 42-year-old. "I know that they'll get it because I got it with my mom. I know they'll get it with me."

That's not to say The Kardashians star—who shares her four kids with ex-husband Kanye West—doesn't have days where she struggles to keep up. 

"Everyone says the days are long and the years are short, and that couldn't be like a more true statement," she said on the podcast. "When you're in it, I mean, especially when they're babies and you're feeding, there's madness going on. It's like full madness. It's the best chaos though."

Though she's taken on the entertainment and fashion industries, built her own empire and has a side gig as an aspiring lawyer, the mogul insisted "parenting is the thing that has taught me the most about myself." 

"It has been the most challenging thing," she continued. "There are nights I cry myself to sleep. Like, holy s--t, this f--king tornado in my house. Like, what just happened?"

At the end of the day, though, it's 100 percent worth it. Bible. 

"It is the most rewarding job in the entire world. It is," she detailed. And while she acknowledges "there is nothing that can prepare you" for the sweetness and the chaos and the pure exhaustion, "You will figure it out, and it will make you so proud of yourself that you figured it out," she added. "And that you got through the day."